How does one sample this seamlessly?

This beat has always blown my mind, and it seems that all of the samples are taken from very different sources. There's the Jaco bassline, then there's the drums and more drums, then throughout the song at least 3 other distinct layers that end up working with each other incredibly. There's a bassline, wah guitar, epic orchestration samples, ambient background noises...

Is this simply the result of looking through thousands of records, or is there something I'm missing? Looking to get more insight into this guys production process.

https://www.youtube.com/watch?v=kj-4kHBHoTQ